• OSHA provides design requirements for handrail and stair rail systems.

Handrails must be not less than 30 inches and not more than 38 inches high, as measured from the leading edge of the stair tread to the top surface of the handrail (see 1910.29(f)(1)(i) and 1910.29, Figure D-12).

Stair rail systems, which provide fall protection, must meet the following height criteria:

• For stair rail systems installed before January 17, 2017, the height must not be less than 30 inches from the leading edge of the stair tread to the top surface of the top rail, per 1910.29(f)(1)(ii)(A); and
• For stair rail systems installed on or after January 17, 2017, the height must not be less than 42 inches from the leading edge of the stair tread to the top surface of the top rail, per 1910.29(f)(1)(ii)(B).

Stairs installed after January 17, 2017, should therefore have two railings: A handrail at no more than 38 inches high, and a stair rail at no less than 42 inches high.

For systems installed prior to January 17, 2017, the top rail of a stair rail system may serve as a handrail only when:

• The height of the stair rail system is not less than 36 inches and not more than 38 inches as measured at the leading edge of the stair tread to the top surface of the top rail (see 1910.29(f)(1)(iii)(A) and 1910.29, Figure D-13); and
• The top rail of the stair rail system meets the other handrail requirements in 1910.29(f).

NOTE: The revisions that took effect January 17, 2017, caused confusion for many employers. The Occupational Safety and Health Administration (OSHA) issued a proposed rule in May 2021 to address the confusion, but later announced an intent to re-open the rulemaking process.

Other criteria for railing found in 1910.29(f) include:

• A minimum clearance for fingers between handrails and any other object of 2.25 inches.
• Handrails and stair rail systems must be smooth surfaced to protect employees from injury, and to prevent catching or snagging of clothing.
• No opening in a stair rail system can exceed 19 inches at its least dimension.
• Handrails and the top rails of stair rail systems must be capable of withstanding, without failure, a force of at least 200 pounds applied in any downward or outward direction within 2 inches of any point along the top edge of the rail.